Note 15 - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Allowance for loan losses	$ 720,047	$ 850,277
Unrealized losses on AFS securities	77,931	170,450
Board of Directors retirement plan	232,748	316,823
Tax credits	0	91,688
Other	413,927	637,497
Deferred compensation	183,155	202,418
Purchase accounting	4,325	38,668
Organizational costs	93,404	169,772
Net operating loss carryforwards	1,014,199	2,456,793
Total deferred tax assets	2,739,736	4,934,386
Deferred tax liabilities:
FHLB stock dividends	(32,412)	(27,820)
Depreciation and amortization	(336,613)	(449,312)
Loan origination costs	(179,185)	(140,237)
Total deferred tax liabilities	(548,210)	(617,369)
Net deferred tax asset before valuation allowance	2,191,526	4,317,017
Valuation allowance:
Balance	0	(4,081,718)
Reversal of valuation allowance	0	4,081,718
Balance	0	0
Net deferred tax asset	$ 2,191,526	$ 4,317,017